The case of the Canadian “Big Maple Leaf” coin provides a lesson in security and the danger of assumptions.

Four individuals are currently on trial in Berlin for the 2017 robbery of the Canadian “Big Maple Leaf”, a solid gold coin worth at least $4 million. The coin, which weighed 220 pounds and was a yard in diameter, was known not only for its large size, but also for its purity. The coin boasted 999.99 of 1000 parts gold, making it one of the purist gold coins in existence. It was also rare. Only five of these coins were minted. In 2007, Guinness Book of World Records named it the largest coin in the world, although Australia has now minted a larger one.

In 2017, thieves stole the coin from the Bode Museum in Berlin. Prosecutors say three of the suspects climbed through an upstairs window to access the area where the coin was held. They then used an axe to shatter bullet-proof case housing the coin. Prosecutors say that after using a rope to hoist the coin out of the museum, they carried it in a wheelbarrow to a waiting car. The case further alleges that the trio succeeded in avoiding security thanks in part to the help of a museum security guard, “Dennis W.,” who is also facing charges.

Four suspects are currently on trial in Berlin for the theft. Ahmed Remmo (20), Wayci Remmo (24), and Wissam Remmo (21) are charged with the crime. Ahmed and Wayci are brothers, and Wissam is their cousin.

Law enforcement believes the three Remmo suspects are members of a Lebanese crime family, the Remmo clan. The family was previously linked to the robbery of a bank outside Mariendorf, Germany, in 2014, stealing more than £8million from safety deposit boxes. One member of the family, Toufic Remmo, served eight years for the robbery.

All four suspects deny involvement in the crime.

Assumptions regarding the coin may have compromised efforts to protect it. Because the coin was iconic, there was a general view that it would be extremely difficult to sell. Buyers would face immediate scrutiny, and would draw the attention of law enforcement, deterring anyone from purchasing a stolen coin. And with no market, there is no motivation for theft.

But this ignored the obvious option, which was to melt down the coin and sell the gold. The value for the thieves was not in the unique coin or in its history, but in the actual gold used to make the coin. Prosecutors say that the coin likely was melted down and sold to gold buyers, and the proceeds were sent to locations outside the country. It is almost impossible to trace, because the gold had no unique properties that would tie it back to the coin.